What Is Nen?

Nen is one of the most versatile power systems in any fictional medium. It is a technique in the anime and manga series Hunter x Hunter that allows a living being to control and manipulate their own life energy, or "aura". While every living being produces aura, only those who are trained can consciously control its flow and harness it for extraordinary abilities. Because of its potential for destruction and chaos, the existence of Nen is kept a secret from the general public.

The Four Major Principles of Nen

When learning Nen, practitioners must practice four core techniques on their path to mastering this expression of power and aura manipulation, including Ten, Zetsu, Ren, and Hatsu.

Ten (Envelop)

The ability to surround one's body with a continuous flow of aura, preventing it from leaking away. This creates a protective shroud and can slow down the aging process.

Zetsu (Suppress)

A technique to halt the flow of aura from the body. Zetsu is useful for masking one's presence from other Nen users and is also effective for recovering from fatigue.

Ren (Refine)

An explosive outburst of aura that dramatically increases a user's physical strength and durability. It serves as the primary offensive technique in Nen.

Hatsu (Release)

The most creative and personal expression of Nen, where a user can project their aura to create a unique supernatural ability. The nature of a person's Hatsu is tied to their specific Nen category.

Advanced Nen Techniques

Once the fundamentals are mastered, Nen users can combine the basic principles to perform more advanced techniques. 

Gyo

Focuses a larger-than-normal amount of aura into one body part, typically the eyes, to see concealed aura.

Ko

A highly offensive and risky technique that combines all four basic principles to focus 100% of one's aura into a single body part. The rest of the body is left completely vulnerable.

En

Extends a user's aura in a sphere to detect anything that enters its radius. The user can sense the shape and movement of anything within this field.

Ken

A defensive technique that maintains a constant state of advanced Ren across the entire body to guard against attacks from any direction.

In

An advanced form of Zetsu that conceals a user's aura, making it impossible to be sensed by others unless they use Gyo.

Limitations and Nen Vows

One of the most powerful aspects of the Nen system is the use of Limitations or Conditions, and Nen Vows. By placing a strict and often personally significant rule on an ability—and sometimes risking severe consequences if the rule is broken—a Nen user can drastically increase its power. A classic example is Kurapika, who swore that he would die if he used Chain Jail on anyone who is not a member of the Phantom Troupe, greatly enhancing the strength of the technique.

The Six Nen Categories

While the affinity of Nen users can fall between the different Nen categories, as noted by author Yoshiro Togashi, every Nen user is born with a primary affinity for one of the six distinct categories. A water divination test is often used to determine a person's primary type. The test consists of a leaf being floated in a glass of water while the user performs Ren, and the result reveals their category:

• Enhancement: The volume of the water increases, causing it to overflow.

• Transmutation: The taste of the water changes.

• Conjuration: Impurities, like dirt or grit, appear in the water.

• Emission: The color of the water changes.

• Manipulation: The leaf floating on the water's surface begins to move.

• Specialization: An entirely different change occurs in the water. This can manifest in a variety of different ways, such as the water changing color and the leaf moving simultaneously, the leaf withering, or the water boiling and producing a foul smell.

Enhancement

Users can strengthen and reinforce their bodies or an object they hold. Gon Freecss is a prime example, using this type to enhance his physical attacks.

Transmutation

Users can change the properties of their aura to mimic something else. For example, Killua Zoldyck transmutes his aura to have the properties of electricity.

Emission

Users can detach their aura from their body and project it over long distances. Emitters can fire aura blasts or create portals, such as Leorio’s remote punch where he punches an object, then projects the aura from his fist to a target at a distance.

Conjuration

Users can create a physical, independent object out of their aura that is visible even to non-Nen users. Kurapika uses this category to conjure his chains.

Manipulation

Users can control living or inanimate objects, and the strength of this control often depends on setting specific, difficult conditions. Illumi Zoldyck’s Needle People technique is a particularly devastating example of manipulation abilities. Illumi can place a needle in a person's head and control them to do his bidding, sometimes to the point of causing their death from overexertion.

Specialization

A catch-all category for unique and rare abilities that do not fit into any other category. Chrollo Lucilfer's ability to steal other people's Nen techniques, known as Skill Hunter, is an example of Specialization.